Figure 10. Diagrams of the construction of the Wrangellia oceanic plateau. From top to bottom, the diagrams depict the eruption environment and growth of the volcanic stratigraphy for areas of Wrangellia flood basalts on Vancouver Island and in Alaska and Yukon. Pre- and post-volcanic sedimentary sequences and underlying Paleozoic arc units are also shown. Most of the units in the sketches are labeled so there is no accompanying legend. Volcanic activity in each of the areas initiated with submarine flows emplaced on pelagic sediments and all of the flood basalts are overlain by Late Triassic limestone.